German Patent Publication DE 4,426,865 describes a control mechanism in which an operable member also referred to as follower or adjustable member can be selectively controlled remotely from two separate locations. The known control mechanism comprises first and second operating levers or control inputs which are connected through respective push-pull cables with a drive lever that in turn is connected to the follower or adjustable member through a switch over element and through a further lever that actuates the follower or adjustable operable member. The switch over element makes sure that an adjustment motion of one of the operating levers releases the other operating or control input levers so that it cannot be operated during operation of one of the levers. Thus, the two operator assemblies cannot influence each other while one of the operator assemblies is being operated. The switch over element is constructed as a symmetric component with lateral recesses. The symmetric component is connected to the free end of the lever that is itself connected to the operable member. Engagement tongues enter selectively into the recesses, whereby these tongues cooperate with the respective control input levers. If one of the two operating levers is actuated, the input lever entrains the lever of the operable member through lateral stops and the engagement tongue of the input lever engages into the recess of the switch over element in order to tilt the switch over element in such a way that the respective other input lever is released end thus prevented from being operable. The mechanism disclosed in German Patent Publication DE 4,426,865 requires a multitude of tiltable levers and other components resulting in a rather complicated and expensive construction that is prone to require substantial maintenance efforts.
German Patent Publication 2,651,134 (Paul), published on May 18, 1977, also discloses an apparatus for connecting two alternately operable operating or input levers with an operable element. Such an apparatus may, for example be used for operating two control cables for reversing a gear in a gear reversing mechanism of a boat motor. The control cables are control input cables the ends of which are connected through a lever and cam follower mechanism to an outgoing or controlled cable for the power transmission. The lever and cam follower mechanism includes cam tracks that are mirror-symmmetrical relative to each other. The mechanism must be so dimensioned that only one power transmitting path can be established at a time from one of the incoming cables to the outgoing cables with the help of at least two mirror symmetrically arranged cam follower rollers (15, 16) or with at least two pipe sections (66, 67) travelling along two oval cam track sections (57, 58) positioned mirror symmetrically opposite each other.
The above described prior art leaves room for improvement, especially with regard to the number of components employed for achieving the intended purpose.